I think...emphasis on think...that the direct drive prop(the one with the larger hole in the middle) is put in the package in the event you purchase the Formosa with the 400 motor. The slowflyer props don't really fit the drive shaft and nut on the 400.

The extra prop is in there because it's cheaper to standardize the packaging to fit a number of different models than to try and only include items for specific models. You have probably noticed that there are also extra trees and plastic parts icluded that are not used on the Formosa.

The HS prop is WAY better than the slowflyer prop. Just use two washers instead of one. My 'seat of the pants' testing with my formosa shows that the HD prop performs better than the APC prop I was using and WAY better than he slowflyer prop

Hi Dax...was this with the stock 350?.....I have found the APC props the best for the brushless set up ....I am working on something that I will use a 350 in ...could be a chance to use my HD props .....I had tried it once in my stock formosa with fuel tubing but went back to a 9x7